Fluid system



FLUID SYSTEM Filed July 18, 1940 2 Sheets-Sheet l INVENTOR. JamwF/ezchez ATTORNEY.

April 18, 1944. J.- FLETCHER FLUID SYSTEM Filed July 18. 1940 2 Sheets-Sheet 2 ATTORNEY.

Patented Apr. 18, 1944 FLUID SYSTEM Jamel Fletcher, Akron, Ohio, minor to The Babcock & Wilcox Company, Newark, N. 1., a corporation of New Jersey Application July 18, 1940, Serial No. 348,174 7 Claims. (Cl. 183-83) This invention relates to fluid systems, and it is more particularly concerned with means for separating fluids of diflferent densities.

The invention may be considered as exemplified by a centrifugal separator, or densifier, which is particularly adapted to be effective upon a large volume of fluid mixtures, per unit of time.

Among other objects, the invention is intended to provide a centrifugal densifler of large capacity, particularly adapted to eilectively operate under conditions imposing severe space limitations.

One embodiment of the invention involves a substantially circular whirl chamber of large diameter, relative to its height. This whirl chamber is provided with a fluid mixture inlet extending over a substantial segment of the circumierence of the chamber, and the inlet is so formed and so separated into a plurality of subinlets by a plurality of vanes that a large volume of fluid mixtures may enter the whirl chamber, per unit of time. Furthermore, a fluid mixture discharged into the whirl chamber is directed eccentrically of the chamber so as to set up a whirling motion therein. As a consequence, a fluid of lower density is separated from one of higher density, and the former passes from the whirl chamber through an upper outlet, while the latter is discharged through a separate outlet.

Another object of the invention is to produce a separator or densiiier which operates efiectively with low pressure drop so that it can be advantageously used where only a small pressure head is available.

The invention contemplates the use of the illustrative separator or densifler in an intermediate drum of a high pressure steam generator. From this drum the separated steam, together with some water, passes through a main steam and water drum in which substantially complete separation of steam and water is effected.

The invention effects marked improvement in the circulatory conditions of a steam generator and enables the latter to operate at a higher drum water level while still supplying dry steam.

Other objects of the invention will appear in the following description which refers to a preferred embodiment illustrated in the accompanying drawings.

In the drawings:

Fig. 1 is a vertical section of a high pressure steam generating installation in which the invention has been applied;

Fig. 2 is a vertical section of the intermediate steam and water drum of the Fig. 1 installation, illustrating the application thereto of the illustrative densiflers;

Fi 3 is an elevation of the illustrative densifier with parts broken away to show the diflerent outlets of separated steam and separated water;

Fig.4 is a horizontal section taken on the line 4-4 of Fig. 3;

Fig. 5 is a longitudinal vertical section through a drum in which a plurality of the illustrative densifiers are employed; and,

Fig. 6 is a horizontal section of the drum taken on the line H of Fig. 5 and showing the arrangement of the densiflers within the drum.

The steam generating installation indicated in Fig. 1 of the drawings is a high pressure central station generator having a maximum design capacity of 600,000 pounds of steam per hour. It involves a primary furnace l0 fired at high temperatures by the burners l2. The combustion gases pass from the bottom of the furnace into the lower part of the second furnace chamber H where radiant heat is transmitted to wall tubes so as to generate steam therein.

Beyond the furnace chamber It, the combustion gases pass, in succession, over the screen tubes t0, the tubes of the superheater l8, and the economizer 20.

Above the eccnomizer 20 is the main steam and water drum 22 from which steam ls'conducted to the superheater l8 and forwardly of this drum is the auxiliary upper drum 24. The v tubes of the screen it are directly connected to the latter drum and the water tubes forming the floor, sides, and roof of the furnace l0 and the chamber l4 have such connections that the major part of the steam and water discharge from these tubes passes directly to the drum 24.

The centrifugal densiflers of the present invention have been installed in the drum 24 and it is significant that, with their installation the circulating flow of the illustrative generator has risen from approximately 3,200,000 pounds per hour to approximately 4,700,000 per hour, one important efiect of this increased circulation rate being the adequate cooling protection of the wall tubes of the furnace I0 when the generator is operating at high capacities.

The illustrative densifier, indicated in Figs. 3

is closed, except for the annularly arranged water outlets 30-33, by a bottom plate 36. This plate is of a diameter, less than the internal diameter of the whirl chamber by an amount equal to twice the width of each of the helical vanes 40. The latter are arranged in the annular passage between the downwardly extending flange on the plate 36 and the side wall of the whirl chamber.

In order to minimize obstruction of the space within the drum 24 by the densifiers, and to provide for adequate flow capacities, the densifiers are relatively large in diameter, and their steam and water mixture inlet for each unit extends over a large fraction of the perimeter of the whirl chamber. As shown in Fig. 4 of the drawings, this inlet, indicated generally by the numeral 42, extends over one-third of the circumference or perimeter of the whirl chamber.

The whirl chamber inlet construction includes a plurality of vanes 44-50 which are arranged substantially tangentially of the whirl chamber and are maintained in their operative positions by securement at their lower ends to an arcuate flange 52 fixed to the side wall of the whirl chamher. The upper ends of the vanes are secured to a flange or rim 54 secured at the top of the whirl chamber.

The drum 24 is separated into two compartments by arcuate plates which may be arranged to form the wall 53. The compartment 58 between the wall 58 and the adjacent drum wall receives steam and water mixtures from the risers 60-68, and the steam and water spaces of the drum are in the drum chamber or compartment 10.

At the upper edge of the wall 53 plates 12 are arranged so ,as to form supporting ledges or shelves for receiving the flanges 52 of the densifiers as indicated in Fig. 2, and all steam and water mixtures discharged into the chamber 58 are compelled to pass through the densifier inlets by reason of diaphragms 59 between adjoining densifiers, and the box plate construction I8, the lower surface of which fits closely against the rim 54 of the inlet as also indicated in Fig. 2.

Each whirl chamber casing is secured in its operative position in the manner indicated in Fig. 2 of the drawings. To accomplish this result, the top of the whirl chamber has fixed thereto an apertured lug 90 which is bolted to the construction 13. A similar apertured lug 92, fixed to the bottom of the whirl chamber, is secured to a bracket 34 fixed to the plate 56.

With a row of the illustrative densifiers arranged as shown in Fig. 2 and disposed longitudinally of the drum, steam and water mixtures are discharged at high rates into the inlet drum chamber 53 through the screen tubes 6064 and the riser connections 65-61 to which the fur nace wall tubes are connected. Thus the pressure head within the chamber 53 causes steam and water to be discharged through the whirl chamber inlets and the tangential passages formed between vanes "-50.

This action sets up a whirling movement of the fluid within each whirl chamber, and the centrifugal efiect causes the separation of the steam and water. The separated steam rises through the large diameter steam outlets 28 of the separators to the steam space 80 of the drum, and thence passes through the circulators 8284 to the steam space of the drum 22.

Separated water passes from the whirl chamhers through the annularly arranged outlets such portion of the whirl chamber velocity head as to permit the densifiers-to operate against a considerable pressure which would otherwise cause water from the water space of the drum to enter the densifier whirl chambers and decrease the separation spaces therein.

The separated water discharged into the drum 24 passes from that drum at its ends through large diameter downcomers 38 and 38 and thence to the headers at the bottom of the furnace II and the furnace chamber l4.

Although the invention has been described with reference to the details of a particular embodiment illustrated in the drawings, the invention is not necessarily limited to all those details, It is rather to be considered as of a scope commensurate with the scope of the subloined claims.

What is claimed is: l

1. In apparatus of the class described, means forming a pressure chamber into which mixtures of fluids of different densities are discharged at high velocities, a diaphragm or wall construction within said chamber dividing it into inlet and outlet compartments the former of which receives all of said high velocity discharges, said diaphragm or wall construction being formed with spaced openings along said chamber, centrifugal densifiers including cylindrical whirl chambers having circumferentially wide inlets set across said openings, said densifiers also including laterally projecting inlet structures set within said openings and including a plurality of vanes spaced apart and so disposed as to direct the fluid mixtures tangentially into the whirl chambers, means at the top of each whirl chamber forming an outlet through which a separated fluid of lower density may pass to the outlet compartment, means associated with each whirl chamber so as to provide restricted outlets through which a separated fluid of higher density is discharged into the outlet compartment, and means for conducting the higher density fluid from the outlet compartment.

2. In apparatus of the class described, a drum into which steam and water mixtures are discharged at high velocities, an upright diaphragm or wall construction dividing the drum into inlet and outlet compartments the former of which receives said high velocity discharges, said diaphragm or wall construction being formed with spaced openings along the drum, centrifugal densifiers including cylindrical whirl chambers set across said openings, said densifiers also including wide inlet structures projecting outwardly of the whirl chambers and projecting through said openings and including a plurality of vanes spaced apart and so disposed as to direct the steam and water mixtures tangentially into the whirl chambers, the whirl chambers with their vaned inlet structures being supported and readily removable by reason of their parts which project through the openings in the diaphragm construction, means at the top of each whirl chamber forming an outlet through which separated steam may pass to the outlet compartment, means associated with each whirl chamber so as to provide restricted water outlets through which the separated water is discharged into the water space of the outlet compartment, and means for conducting water from the outlet compartment.

3. In apparatus of the class described, means forming a pressure chamber into which mixtures of fluids of different densities are discharged at as those shown at 30-43, retaining such a pro- 7 high velocities, an upright diaphragm on t tion within said chamber dividing it into'inlet and outlet compartments the former of which receives all of said high velocity discharges, said diaphragm construction being formed with spaced openings through which all of said iluid passes, centrifugal densifiers including upright cylindrical whirl chambers set across said openings, said densifiers also including laterally proiecting inlet structures set within said openings to support the whirl chambers and including a plurality of tangentially arranged vanes spaced apart and so disposed as to direct the fluid mixtures tangentially into the whirl chambers, means at the top of each whirl chamber forming an outlet through which a separated fluid of lower density may pass at decreased velocity to the outlet compartment, means associated with each whirl chamber so as to provide a restricted outlet through which a separated fluid of higher density is discharged into the outlet compartment, and means for conducting the higher density fluid from the outlet compartment.

4. In a fluid system, an exterior fluid chamber, an upright wall dividing said chamber into outlet and inlet compartments into the latter of which mixtures of fluids of different densities are discharged under pressure, casings forming the whirl chambers of centrifugal separators disposed in the outlet compartment and having laterally projecting inlet structures communicating with the inlet compartment through spaced openings in said wall, the inlet structure of each whirl chamber casing being laterally fitted to the wall and extended through one of said openings for support by the wall and quick detachability therefrom, means above and/or below the inlet for securing each casing to the wall, each separator having a first outlet through which separated liquid is discharged to the lower, part of the outlet compartment and a second outlet through which, a separated vapor or gas passes to the upper part of the outlet compartment.

5. In apparatus of the class described, means forming a pressure chamber into which mixtures of fluids or diflerent densities are discharged under pressure, an upright diaphragm or wall construction dividing said chamber into inlet and outlet compartments the former of which receives said mixtures, said diaphragm or wall construction being formed with spaced openings, centrifugal densifiers including casings forming cylindrical whirl chambers, said densifiers including circumferentially wide inlets formed by laterally projecting inlet structures communicating with the inlet compartments through said openings and so constructed and disposed as to direct the fluid mixtures tangentially into the whirl chambers, said wall construction and the casings having inter-engaging parts whereby the whirl chamber casings are guided into their operative positions (during replacement) and given vertical support by the wall, means at one end of each whirl chamber forming an outlet through which a separated fluid of lower density passes at decreased velocity to the upper part of the outlet compartment, means associated with each whirl chamber so as to provide restricted outlets through which a separated :tiuid of higher density is discharged into the outlet compartment, and

means for conducting the lower density fluid from the outer compartment.

6. In combination, a steam and water drum, a diaphragm construction dividing the drum into inlet and outlet compartments and provided with spaced openings along an upright part thereof, whirl chamber casings having laterally projecting inlets communicating with said inlet compartment openings, and whirl chamber-inlet compartment connections including spaced elements associated with the diaphragm and combining with said projecting inlet structures to constitute inter-engaging parts slidably guiding the whirl chamber casings into their operative positions and providing vertical support therefor.

7. In combination, means forming a gas and liquid chamber, a diaphragm construction dividing the chamber into inlet and outlet compartand combining with said projecting inlet structures to present inter-engaging parts slidably guiding the whirl chamber casings into their operative positions and providing vertical support therefor.

- J AMES FLETCHER 

